Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com
 
MPD1
Go Back   Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com > Engine | Drivetrain | Powertrain Technical Discussions > Forced Induction - V8

Forced Induction - V8 V8 Supercharger, turbo, nitrous discussions

Reply
 
Thread Tools
Old 11-09-2010, 07:08 AM   #1
B-rad
Yellow Stealth
 
Drives: 2010 2SS Camaro, 1999 WS6 Trans Am
Join Date: Apr 2010
Location: Midwestern Ontario, Canada
Posts: 105
Smaller blower pulley or bigger crank pulley?

I've got a maggie 2300 with a 3.6" pulley. I want to up the boost, just not sure which way to go. I know it is easier to downsize the blower pulley, but I don't want to have belt slippage.

Does anybody know how much boost is gained going to a 10% overdrive crank pulley vs. downsizing the blower to a 3.4" or 3.2"?
B-rad is offline   Reply With Quote
Old 11-09-2010, 07:26 AM   #2
Supercharged SS
Account Suspended
 
Drives: 2010 Camaro
Join Date: Feb 2010
Location: Sandy Hook, CT
Posts: 12,021
Quote:
Originally Posted by B-rad View Post
I've got a maggie 2300 with a 3.6" pulley. I want to up the boost, just not sure which way to go. I know it is easier to downsize the blower pulley, but I don't want to have belt slippage.

Does anybody know how much boost is gained going to a 10% overdrive crank pulley vs. downsizing the blower to a 3.4" or 3.2"?
You should be able to run a 3.4 with no problem. I got 10.5 psi with a 6 rib 3.4. You could prob even run a 3.2 with no slippage too. I have a brand new 3.2 with the gator grip process machined into it if you're interested. That should make about 12 - 12.5 psi.
Supercharged SS is offline   Reply With Quote
Old 11-09-2010, 11:56 AM   #3
B-rad
Yellow Stealth
 
Drives: 2010 2SS Camaro, 1999 WS6 Trans Am
Join Date: Apr 2010
Location: Midwestern Ontario, Canada
Posts: 105
Quote:
Originally Posted by Supercharged SS View Post
You should be able to run a 3.4 with no problem. I got 10.5 psi with a 6 rib 3.4. You could prob even run a 3.2 with no slippage too. I have a brand new 3.2 with the gator grip process machined into it if you're interested. That should make about 12 - 12.5 psi.
PM me with a price.

Any Idea how much boost is safe to run on a stock LS3 on 91 octane gas? I plan on doing water/meth injection as well.
B-rad is offline   Reply With Quote
Old 11-09-2010, 12:02 PM   #4
lewylew

 
lewylew's Avatar
 
Drives: 2010 ZL550
Join Date: Feb 2010
Location: Near Philadelphia
Posts: 1,204
I would keep it under 10 PSi without the meth. With the meth you should be alright upto 12 or a little more. SuperchargedSS is running 12.5 on stock bottom end. I am no expert though.

I would like to know the answer to your original question about the overdrive pulley as well
lewylew is offline   Reply With Quote
Old 11-09-2010, 12:39 PM   #5
Supercharged SS
Account Suspended
 
Drives: 2010 Camaro
Join Date: Feb 2010
Location: Sandy Hook, CT
Posts: 12,021
Quote:
Originally Posted by lewylew View Post
I would keep it under 10 PSi without the meth. With the meth you should be alright upto 12 or a little more. SuperchargedSS is running 12.5 on stock bottom end. I am no expert though.

I would like to know the answer to your original question about the overdrive pulley as well

B-rad, I answered your pm.

Also, Brad, as I asked in the pm, whats your elevation? Whats makes 10 or 12 psi down (sea level) here won't if you are at a high elevation or if you are planning on adding headers, (if you don't already have them) or a cam down the road. you may make only 10 psi with a 3.2. There is a formula floating around the will "ballpark" your boost.
Supercharged SS is offline   Reply With Quote
Old 11-09-2010, 07:53 PM   #6
B-rad
Yellow Stealth
 
Drives: 2010 2SS Camaro, 1999 WS6 Trans Am
Join Date: Apr 2010
Location: Midwestern Ontario, Canada
Posts: 105
Quote:
Originally Posted by Supercharged SS View Post
B-rad, I answered your pm.

Also, Brad, as I asked in the pm, whats your elevation? Whats makes 10 or 12 psi down (sea level) here won't if you are at a high elevation or if you are planning on adding headers, (if you don't already have them) or a cam down the road. you may make only 10 psi with a 3.2. There is a formula floating around the will "ballpark" your boost.
The elevation where I live is about 1000ft, but the place I had my car dynoed is about 570ft. I don't have a boost guage yet, but during the dyno the boost maxed out at about 7.5 PSI. That is with LT headers and the 3.6" pulley.
B-rad is offline   Reply With Quote
Old 11-10-2010, 10:28 AM   #7
Jessika
Account Suspended
 
Drives: Anything Blown
Join Date: Aug 2010
Location: SoCal
Posts: 1,197
Quote:
Originally Posted by B-rad View Post
I've got a maggie 2300 with a 3.6" pulley. I want to up the boost, just not sure which way to go. I know it is easier to downsize the blower pulley, but I don't want to have belt slippage.

Does anybody know how much boost is gained going to a 10% overdrive crank pulley vs. downsizing the blower to a 3.4" or 3.2"?
Do you have the actual size of the crank pulley in question? I have a calculation that I can plug the info into if you do.
Jessika is offline   Reply With Quote
Old 11-10-2010, 10:29 AM   #8
Ernie@P
 
Drives: 1998 Formula
Join Date: May 2010
Location: Phoenix
Posts: 89
go with the larger lower so you dont have an issue with belt wrap and slip on the upper
Ernie@P is offline   Reply With Quote
Old 11-10-2010, 10:58 AM   #9
Supercharged SS
Account Suspended
 
Drives: 2010 Camaro
Join Date: Feb 2010
Location: Sandy Hook, CT
Posts: 12,021
Quote:
Originally Posted by Ernie@PSR View Post
go with the larger lower so you dont have an issue with belt wrap and slip on the upper
I think the od pulley is only offered in an 8 rib and costs around $550 which is half the cost of the entire 8 rib set up. It make sense to bite the bullet and go with the entire 8 rib if you plan on changing the bottom. Then you can run whatever blower pulley you want and be good to go.
Supercharged SS is offline   Reply With Quote
Old 11-10-2010, 11:37 AM   #10
Jessika
Account Suspended
 
Drives: Anything Blown
Join Date: Aug 2010
Location: SoCal
Posts: 1,197
If you run a 9" crank pulley you can run a 3.6 @ 12lbs easily.
The stock crank pulley should be 7.527
Jessika is offline   Reply With Quote
Old 11-13-2010, 07:03 AM   #11
B-rad
Yellow Stealth
 
Drives: 2010 2SS Camaro, 1999 WS6 Trans Am
Join Date: Apr 2010
Location: Midwestern Ontario, Canada
Posts: 105
I think just because of the extra cost in installing a overdrive crank pulley, I am going to go with the 3.2" blower pulley. If I end up having an issue with slippage, I guess I will know what I have to do.
B-rad is offline   Reply With Quote
Old 11-13-2010, 08:09 AM   #12
old motorhead

 
Drives: Maggie blown LS3 vette
Join Date: Aug 2009
Location: SE TX
Posts: 1,291
By keeping your crank pulley stock sized, you're not turning all of your other accessories faster than necessary. The proponents of under driven crank pulleys, for n/a builds, claim a 10 rwhp gain from turning the accessories slower. If you turn them faster......well, you get the idea.
old motorhead is offline   Reply With Quote
Old 11-13-2010, 09:24 AM   #13
PoleCat2SSRS2010
R6P Marketing Lab Rat
 
PoleCat2SSRS2010's Avatar
 
Drives: 2010 2SSRS for weekends mostly
Join Date: Feb 2009
Location: Texas
Posts: 328
Quote:
Originally Posted by Jessika@Magnacharger View Post
If you run a 9" crank pulley you can run a 3.6 @ 12lbs easily.
The stock crank pulley should be 7.527
(Disclaimer: if all research and tech information from a competitor's web site is correct)

I am not attacking anyone here so please don't take this personal. Just trying to clear the air or my potential confusion.

With a 3.6 SC pulley and a 7.5 crank pulley this means his ratio is ~2.07:1 and multiply that times the engine RPM limit 6500 and a blower RPM of 13448 should get the estimated boost rated at sea level of ~11 psi.

Does being at 1000FT above sea level reduce boost pressure by 4 lbs?

Also isn't the 9 inch crank pulley about 3 sizes larger if they go up by .5 in increments?

Isn't each increment in crank pulley size supposed to change the boost by 4 psi? (again if research is correct)

Wouldn't the 8 inch crank pulley be the preferred size with the 3.6 SC pulley add 4 psi onto the OP's current rating of 7.5 and he should get 11.5? (pushing the limit of stock internals only if he were to take it to 6500 RPM or higher. He might actually have to go up on SC pulley size to a 3.75 to get back down to ~10 psi)

A 9 in is 3 sizes up and would normally add 12 psi making a total of 19.5 psi with the 3.6 SC pulley instead of a total of 12 with the 3.6?

Also, this is with all of the OP's engine internals and exhaust remaining the same.
__________________
PoleCat2SSRS2010 is offline   Reply With Quote
Old 11-13-2010, 10:00 PM   #14
Jessika
Account Suspended
 
Drives: Anything Blown
Join Date: Aug 2010
Location: SoCal
Posts: 1,197
Quote:
Originally Posted by PoleCat2SSRS2010 View Post
(Disclaimer: if all research and tech information from a competitor's web site is correct)

I am not attacking anyone here so please don't take this personal. Just trying to clear the air or my potential confusion.

With a 3.6 SC pulley and a 7.5 crank pulley this means his ratio is ~2.07:1 and multiply that times the engine RPM limit 6500 and a blower RPM of 13448 should get the estimated boost rated at sea level of ~11 psi.

Does being at 1000FT above sea level reduce boost pressure by 4 lbs?

Also isn't the 9 inch crank pulley about 3 sizes larger if they go up by .5 in increments?

Isn't each increment in crank pulley size supposed to change the boost by 4 psi? (again if research is correct)

Wouldn't the 8 inch crank pulley be the preferred size with the 3.6 SC pulley add 4 psi onto the OP's current rating of 7.5 and he should get 11.5? (pushing the limit of stock internals only if he were to take it to 6500 RPM or higher. He might actually have to go up on SC pulley size to a 3.75 to get back down to ~10 psi)

A 9 in is 3 sizes up and would normally add 12 psi making a total of 19.5 psi with the 3.6 SC pulley instead of a total of 12 with the 3.6?

Also, this is with all of the OP's engine internals and exhaust remaining the same.
Is all this info based on a jackshaft system? I threw the 9" crank diameter (just guessing a number) into the calculator and that's what I got. Without being at work with resources it seems that is all direct drive stuff.

I am no blower genius... I rely on the amazing engineers and staff to teach me...

And 3000 above sea level results in a 1 lb loss...


Sent from my non amazing and not awesome iPhone4
Jessika is offline   Reply With Quote
Old 11-14-2010, 12:09 AM   #15
PoleCat2SSRS2010
R6P Marketing Lab Rat
 
PoleCat2SSRS2010's Avatar
 
Drives: 2010 2SSRS for weekends mostly
Join Date: Feb 2009
Location: Texas
Posts: 328
Quote:
Originally Posted by Jessika@Magnacharger View Post
Is all this info based on a jackshaft system? I threw the 9" crank diameter (just guessing a number) into the calculator and that's what I got. Without being at work with resources it seems that is all direct drive stuff.

I am no blower genius... I rely on the amazing engineers and staff to teach me...

And 3000 above sea level results in a 1 lb loss...


Sent from my non amazing and not awesome iPhone4
Good point but isn't the OP running a 1:1 rear pulley set up thus simulating the direct drive RPMs?
If not then those ratios need to factored into the RPM formulation.

(I really admire your dedication to post from the iPhone. I have an Evo and I am just too lazy....I wait til I am on a terminal.)
__________________
PoleCat2SSRS2010 is offline   Reply With Quote
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
DIY : Install underdrive pulley on 2010 Camaro SS Nine Ball Camaro DIY & HOW-TO instructions & discussions 34 09-30-2013 08:25 PM
Quick question on tvs pulleys boostedyards86 Forced Induction - V8 19 04-29-2010 09:04 AM
Overdrive crank pulley questions? Supercharged SS Forced Induction - V8 9 04-27-2010 07:10 PM
Calling Shorty Header Owners Inferno2SS Camaro V8 LS3 / L99 Engine, Exhaust, and Bolt-Ons 87 04-05-2010 01:59 AM
Smaller pulley for TVS2300 magnacharger? SoloSK71 Forced Induction - V8 15 09-02-2009 09:46 AM


All times are GMT -5. The time now is 06:46 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.